Electric-arc lamp.



UNITED STATES PATENT GFFICE. EZEGI-IIEL WEINTRAUB, F SCI-IITNEADY, NEW YORK, ASSIGN OI} T0 GENERAL ELECTRIC ClOlVIPANY, .A GORJPORATION 0F YORK,

ELECTRIC-ARC LAMP.

Specification of Letters Patent.

Patented Apr. 2, 1912.

-- Application filed November 17, 1904. Serial No. 233,083.

To all whom it may concern:

Be it known that I, Eznorrnn. \VEIN- TRAUB, a subject of the Czar of Russia, residing at Schenectady, county of Schenectady, State of New York, have invented certain new and useful Improvements in Electrio-Arc Lamps, of which the following is a specification.

The invention herein described comprises a novel form of arc lamp in which the arc takes place in a neutral gas such as hydrogenand between electrodes, one at least of which is of vaporizable material. The are may be of a length commensurate with that of ordinary arcs, as for example from a fraction of an inch to an inch or more in length, and hasa potential gradient similar to that of ordinary arc lamps. The are can be run at small currents below one ampere even, and with small consumption of energy in some cases, as low as 50 to 7 0 watts. The electrodes do not waste away so that the life of the lamp is practically indefinite.

The features of novelty which characterize my invention I have endeavored to pointout with particularity in the appended claims.

The invention itself, however, will be better understood by reference to the following description taken in connection with the accompanying drawings, which represent, by way of illustration, one of the numerous embodiments which my invention may assume in p actice.

My improved arc lamp comprises in the first place, a gas-tightenvelop or COXlifllllQl,

preferably or conveniently of glass. Such a container is indicated at 1 and is-surmounted as'indicated by a cooling or expansion chamher 2. This container or envelop is provided with electrodes which are in contact with each other when the lamp is not working and which are slowly separated for starting the are. One at least of these electrodes is of some suitable vaporizable material, such as mercury, while the other electrode may be of vaporizable material also or of some non-vaporizablc -material such as iron, graphite, or the like. The mercury electrode in the present instance is represented at 3 and is contained, in the particular form of lamp shown, in the lower U-shaped portion of the envelop or container 1. An electrode 4 of graphite is represented as supported by arc is of the desired length.

nientmay be -made automatic by means of envelop 1 and makes contact, when the lamp is out of operation, with the body of mercury 3.

In order to start the lamp some means for slowly separating the electrodes is employed.

One such means may consist of acoil or heating conductor 6 about the chamber 1. This heating conductor is represented as in series with the lamp, and when heated causes the neutral gas in the container to expand and thereby force the mercury 3 down the adjacent leg of the container.and up the outside leg 7. This operation takes place slowly and thus gives the are a chance to start. If a rapid separation of the electrodes were made the parts not being allowed to heat up the arc would be unable to maintain itself and would go out. As soon as an initial arc is produced the heat generated thereby assists somewhat in producing an expansion of the gas in the envelop and thereby forces down the mercury column still farther and so lengthens the are. This lengthening takes place until the counter pressure exerted on the upper portion 8 of the leg 7 increases su-flic-iently to prevent any further movement. The parts condition. of equilibrium is established the This adjustthe heating coil 9 connected in shunt to the are and located about the part 8.

Inasmuch as the voltage consumed in the arc is utilized in a. short arc length the temperature of the arc is correspondingly high.

of the lamp are adjusted so that when-this f Therefore, in order to protect the adjacent walls of the are either entirely or atlthe poin't whence it emerges from the mercury electrode, in other, words, the cathode spot, with a tube or sleeve ofa refractory material such, as fused quartz or silica. Such a tuberepresentedat 10 and is arranged, either to float in the mercury, or is fixed in relation to the walls of the main envelop by means of registering indentations 11 and 12.

I have referred to the presence of-J'an inert gas in the main envelop and surrounding the electrodes. Anyone of a number of gases may be employed for this purpose. Hydrogen, for example, gives very good results, though other gases can be used suchas carbon monoxid, carbon dioxid, hydro glass envelop, I surround the low and may be in the neighborhood of a tenth of an atmosphere.

In the operation of the lamp and particularly during starting, it is very desirable that the gas pressure in the lamp should not rise unduly, for the reason that the arc volt-' age depends to some extent upon the pressure and rises as the pressure rises. Therefore in starting it the pressure rises too fast the voltage also rises and the arc becomes unstable and goes out. The cooling chamher 2 is therefore of considerable size so as to prevent anysudden change of gas pressure.

/Vhat I claim as new and desire to secure by Letters Patent of the United States, is,

1. In an electric arc lamp, the combination of a gastight envelop, an inert fixed gas therein, are maintaining electrodes in said envelop initially contacting with each other, and means operating on said gas to separate saidelectrodes before the arc starts. p

.2. In an electric arc lamp, the combination of a gas-tight envelopprovided with a bent portion, a body-of mercury located in said bent portion but not completely filling it, a cooperating solid electrode forming with said body of mercury the terminals of a relatively short arc, and inert gas at moderate pressure in said envelop .on both sides of said mercury.

3. In an electric arc lamp, the combination of an arc-inclosing envelop an atmosphere of gas therein, a fluid electrode, and a refractory sleeve su'fliciently large to permit free motion of the cathode spot and inclosing onits surface the active portion of said electrode.

4. In an electric device, the combination of a gas-tight envelop, a considerable quantity of inert fixed gas therein, cooperating electrodes normally in contact when the .lamp is in inoperating condition, and means for increasing the gas pressure to separate said electrodes.

5. In an electric arc lamp, the combination of a gas-tight envelop, gas at considerable absolute pressure in said envelop, electrodes in said envelop, thermal means in series with said electrode for separating said electrodes and thermal means in shunt with said are for causing said electrodes to approach one another.

6. In a vapor device, the combination of an envelop having a condensing chamber, a substantial quantity of a fixed gas therein, electrodes in said envelop, and means for automatically varying the pressure of said fixed gas in said condensing chamber to start an are between said electrodes.

7. In a vapor device, the combination of an envelop, a stationary electrode and a body of mercury therein, means for maintaining a moderate gas pressure on opposite sides of said body of mercury and means for varying this pressure to start and maintain ashort hot are between said stationary electrode and said body of mercury.

In witness whereof, I have hereunto set my hand this 15th day of November, 1904:.

EZECHIEL IVEINTRAUB.

Witnesses:

BENJAMIN B. HULL, HELEN Onrono. 

